Changes in pCO2 during air medical transport of children with closed head injuries.

OBJECTIVES

Because low partial pressure of carbon dioxide (pCO2) can be associated with posttraumatic cerebral ischemia, we conducted a study to determine whether the pCO2 level in ventilated children with closed head injuries transported by a trained team to tertiary care was optimally maintained during transport and determine whether hand-bagging or mechanical ventilation resulted in more optimal pCO2 levels after transport.

METHODS

We reviewed the hospital charts and transport records of all infants and children who had sustained a head injury and were transported by a specialized pediatric transport paramedic team to a single tertiary care facility during a 12-month period. All children were intubated and ventilated either mechanically or manually. Outcome measures were final pCO2 before transport and first pCO2 on arrival in the PICU.

RESULTS

Twenty-nine children (age 0.6 to 16 years, mean 7.3, median 6) met the criteria. Fourteen patients were hand-bagged (HB), and 15 were mechanically ventilated (MV). Eleven patients (5 HB and 6 MV) started in the target pCO2 range of 35 to 40 mmHg. After transport, nine patients (all MV) had pCO2 within the target range (P < 0.01). Duration of transport (mean 63 minutes, range 15-200 minutes) did not contribute to the final pCO2 level.

CONCLUSION

MV improves management of pCO2 during interfacility transport. HB significantly increases the incidence of suboptimal pCO2 and hence the risk of suboptimal cerebral blood flow. MV appears mandatory, and monitoring CO2 in transit (end-tidal or preferably point-of-care testing) should further reduce the likelihood of secondary complications from cerebral ischemia.